Extract audio to file from movie clip - with Blender?
Currently there isn't a node with that capability built in. The simplest that you might script is the following:


add the clip to the VSE
set start and endframe: bpy.context.scene.frame_start  and .frame_end
call the mixdown operator: bpy.ops.sound.mixdown (see the docs for parameters)
reset frame start/end if you need to.


something like this.

import bpy

def main(filepath_source, filepath_destination, frame_start=0, frame_end=20):
    scn = bpy.context.scene

    scn.frame_start = frame_start
    scn.frame_end = frame_end

    if not scn.sequence_editor:
        scn.sequence_editor_create()

    sequences = scn.sequence_editor.sequences
    sequences.new_sound(
        name='drone_detroit', 
        filepath=filepath_source,
        channel=0, frame_start=0
    )
    bpy.ops.sound.mixdown(filepath=filepath_destination)   

fp_source = r"C:\Users\zeffi\Downloads\DRONE\0001-2964.avi"
fp_destination = r"C:\Users\zeffi\OneDrive\Documents\chopper_drone4.flac"

main(fp_source, fp_destination, frame_start=500, frame_end=560)


the sequences.new_sound, lifts the audio track off the .avi.

The mixdown operator will output the audio of whatever is between those two frames.